import java.util.Arrays;

public class Test1 {

    public static void main(String[] args) {
        /*int a;
        int b;
        System.out.println(a);
        System.out.println(b);*/
       /* A a = new A();
        //B b = new B();

        System.out.println(a.a);
        System.out.println(b.b);*/
        A a1 = new A();
        A a2 = new A(10);
        //A a3 = new A(10,20);
    }
}
class A {

    public int a = 10;
    public int b = 20;
    public int c = 30;
    public int d = 40;

public A() {
    this(30);
    //System.out.println("这是A的构造方法");
}
public A(int a) {
        this(10,20,30,40);
    //System.out.println("这是带有一个参数的构造方法");
}
public  A(int a, int b,int c, int d) {
    this.a = a;
    this.b = b;
    this.c = c;
    this.d = d;

    //System.out.println("这是带有两个参数的构造方法");
}
}
/*
class B {

public int b;

public B() {
        b = 20;
    System.out.println("这是B的构造方法");
}
}
*/
